It turns out that "fish wholesaler" and "toy designer" are not mutually exclusive professions: Kazuyoshi Watanabe, a Tokyo fish wholesaler, created this wooden tuna to teach people how to properly loin the fish.

The model comes with just about everything you need to get the job done—including a cutting board a long knife to do the cutting. The model itself is much like any other anatomical version you've probably seen—each piece comes apart and then stacks back together for easy storage.